package com.fan.dao;

import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;

public class BaseDao {
    private static String driver;
    private static String url;
    private static String username;
    private static String password;


    static {
        Properties properties = new Properties();
        InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.properties");
        try {
            properties.load(is);
        } catch (IOException e) {
            e.printStackTrace();
        }
        driver = properties.getProperty("driver");
        url = properties.getProperty("url");
        username = properties.getProperty("username");
        password = properties.getProperty("password");
    }


    public static Connection getConnection(){
        Connection connection = null;
        try {
            Class.forName(driver);
            connection = DriverManager.getConnection(url, username, password);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return connection;
    }


    //查询公共类
    public static ResultSet execute(String sql,Object[] params,Connection connection,PreparedStatement preparedStatement,ResultSet resultSet)throws SQLException {
        preparedStatement = connection.prepareStatement(sql);
        for (int i=0;i<params.length;i++){
            preparedStatement.setObject(i+1,params[i]);
        }
        resultSet = preparedStatement.executeQuery();
        return resultSet;
    }

    //执行Update语句
    public static int execute(String sql,Object[] params,Connection connection,PreparedStatement preparedStatement)throws SQLException {
        preparedStatement = connection.prepareStatement(sql);
        for (int i=0;i<params.length;i++){
            preparedStatement.setObject(i+1,params[i]);
        }
        return preparedStatement.executeUpdate();
    }

    //关闭连接
    public static boolean closeResource(Connection connection,PreparedStatement preparedStatement,ResultSet resultSet){
        boolean flag = true;
        if (resultSet!=null){
            try {
                resultSet.close();
                resultSet = null;
            } catch (SQLException e) {
                e.printStackTrace();
                flag = false;
            }
        }

        if (preparedStatement!=null){
            try {
                preparedStatement.close();
                preparedStatement = null;
            } catch (SQLException e) {
                e.printStackTrace();
                flag = false;
            }
        }

        if (connection!=null){
            try {
                connection.close();
                connection=null;
            } catch (SQLException e) {
                e.printStackTrace();
                flag=false;
            }
        }
        return flag;
    }
}

































